Fire extinguisher



Oct. 7, 1941. H. M. SALMOND ET AL FIRE EXTINGUISHER Filed Oct. 23, 1939 Attam y Patented Oct. 7, 1941 rum nx'rmcmsnaa Hubert Mackenzie Salmond, Fareham, and Anden Mathisen. High Holborn, London, England, assignors to Graviner Manufacturing Company Limited, London, England Application October 23, 1939, Serial No. 300,832 In Great Britain November 4, 1938 6 Claims. (Cl. 29995) The invention relates to fire extinguishers of the type in which a quantity or fire extinguishing liquid such as carbon-tetra-chloride or methylbromide is stored under gas pressure in a metal bottle having a discharge orifice which may be opened when required to permit the liquid to be expelled from the bottle at a high velocity under the gas pressure.

One object of the invention is to provide in such extinguishers means enabling at least some of the liquid to be expelled by the gas at its maximum pressure when required, irrespective of the position in which the extinguisher may be.

Another object of the invention is to provide means of this kind which will be light in construction enabling the extinguisher to be used with advantage on aircraft.

A further object is to construct such means in a compact form enabling them to be introduced in their assembled form into the bottle through the mouth thereof.

A still further object of the invention is to provide means of the above kind which may be incorporated with a closure member for the bottle so as to be supported thereby within the bottle when the closure member is sealed in the mouth of the bottle.

' Yet another object of the invention is to provide discharge mechanism for fire extinguishers of the type set forth, which will be simple in construction and positive in operation.

7 The foregoing and other objects 01' the invention will be apparent from the following description of a preferred form of construction of the invention read in conjunction with the accompanying drawing, in which Fig. 1 shows in longitudinal cross-section a metal bottle type fire extinguisher constructed of solid drawn metal and equipped. with discharge mechanism according to the invention; Fig. 2 is a sectional view along the line 2-2 of Fig. 1 and Fig. 3 is a sectional view taken along the line 3-3 of Fig. 1.

Referring to the drawing, a solid drawn metal bottle I of substantially cylindrical shape having a tapering neck portion 2 terminating in a mouth I of substantial size, constitutes the container for the liquid to be stored in under gas pressure of about 60 lbs. per square inch. The bottle is provided with a handle 4 in the usual manner, and the end 01' the mouth portion I is screw-threaded to accommodate a discharge control head 5, which is oi! the usual form for operationby remote control.

The end or the mouth portion 3 is bevelled internally to accommodate the chamfered circumierential edge of a closure member 6 comprising a metal disc which is securely held in position in the mouth of the bottle by means of the head i, this head being soldered to the neck 2 of the bottle alter assembly as shown at I. The disc is formed with a short cylindrical portion which is a push fit in the internally machined neck of the bottle.

Three hard brass conduit pipes such as the two pipes 8 and 8 shown in the drawing, are secured each at one end thereof in circumferentially spaced holes in the closure disc 6, in which holes they are a driving fit and to which disc they are secured by shrinkage and spinning over of the ends so that they do not loosen or come adrift as the result of vibration. At their other ends, these conduit pipes are secured in a similar manner in circumferentially spaced holes in a flanged disc l0 forming part of a collecting chamber II.

The flange on the disc- I0 is screw-threaded internally at its outer end and accommodates a disc l2 forming the closure member for the chamber, the end of the flange being spun over the outer surface of the disc I! to form a fluid-tight fit between these parts. The outer surface of the flange is a sliding lit in the bottle neck so as to permit easy insertion of the chamber into the bottle. The discs l0 and I! are drilled centrally to accommodate with push fits two supply tubes it and I4, which are arranged as shown in the drawing to extend axially oi the container] on opposite sides of the collecting chamber II, the tube 13 being located between the three conduit pipes. The tubes l3 and I4 are shrunk into the discs III and I2 respectively so as to renderthe joints fluid-tight, and their ends are spun over to avoid loosening, the free ends of the tubes being arranged to extend close to the respective ends of the bottle I, and in the centers of these ends.

The free ends 01' the tubes I3 and II are ground to form seatings for closure valves [5 and i6 respectively which are secured at the opposite ends of a brass rod II, the length of which is greater than the distance between the two seatings so that only one of the valves can be closed at any one time. The valves are constructed of substantially thin metal plates ground at their edges to seat in a fluid-tight manner on their respective seatings and are provided with hollow stems such as the stem it, through which a turned down end portion." of the red I! is passed to be riveted over at its end as shown at I 9. v I

Each valve is provided on its stem with three clrcumferentially spaced radial vanes such as the vanes II and I2, theouter edges of which vanes slidably ht the tubes i3 and II so as to ensure the true axial movement of the valves with respect to the tubes. 'Ihe axial length of the vanes is greater than the maximum possible lift of the valves so that the inner parts of the vanes always remain within the tubes.

The valve rod i'l serves as a gravity biasing device to ensure that the valve which is uppermost is closed and the other valve open, irre-- spective of the position of the bottle. In the normal position of the bottle as shown in the drawing. the valve II is closed and the valve I5 is open. Such an arrangement enables the gas under pressure at the upper end of the bottle to force valve ll onto its seating and to force the liquid at the bottom of the bottle through the valve opening at the bottom of the tube ll, up the tube l8 and into the collecting chamber II from where it is forced through the conduit pipes such as 8 and 8 into the control head 5 and so out of the bottle at high velocity under the full pressure of the gas.

If the bottle is inverted when required to be used, such as may be the case for example when fitted to an aircraft which has turned turtle on landing, the valve it which is then uppermost is automatically closed due to the weight of the rod l1, and the liquid is forced through the valve opening at the end of the tube i4 and so up the tube It to the collecting chamber II and thence through the conduit pipes such as 8 and 9 to the discharge head.

If the bottle happens to be lying with its major axis horizontal when required to be used, either valve may be open, or both valves may be partly open each. As the bottle is three-quarters full of liquid, the surface of the liquid will be above the ends of both tubes i3 and II, so that the liquid will be forced along either or both tubes, according to the position of the valves, to the collecting chamber from where it will pass to the discharge head through the conduit pipes.

It will be readily seen that in any inclined position of the bottle, the liquid will pass to the collecting chamber ii through the supply tube which happens to be lower than the other supply tube, when the discharge head is operated.

Having thus fully described our invention, what we claim as new and desire to protect by Letters Patent is:

l. A fire extinguisher comprising in combination, a metal bottle, a discharge head secured in a fluid-tight manner on to the mouth of the bottle, discharge control means associated with said discharge head, an interior closure member sealing the mouth of the bottle from said discharge head, circumferentially spaced passageways in said closure member. conduit pipes passing through said passageways in a fluid-tight manner, and extending into said bottle, a collecting chamber supported at the ends of said conduit pipes within the bottle and communicating therewith in a fluid-tight manner, a supply tube supported by said collecting chamber and communicating therewith in a fluid-tight manner, said tube extending axially of the said bottle and between the said bottle and between the said conduit pipes to near the mouth end of the bottle, another supply tube supported by said collecting chamber and communicating therewith in a. fluid-tight manner, said other tube extending axially of the bottle in the opposite direction to said first mentioned tube to near the end of the bottle remote from the mouth thereof, valve seatings at the rea sence mote ends of said supply tubes, a closure valve co-operating with each seating, a rod connecting said valves together inspaced-axial relation and acting by gravity to close the valve which is uppermost and open the other valve and guide means-serving to guide the valves axially of the said supply tubes.

' 2. A fire extinguisher, comprising: a one piece container having a relatively wide mouth, a closure plate fitted to said relatively wide mouth, a discharge head attached to said container around the mouth thereof, said discharge head clamping said slosure plate into said mouth, a plurality of conduit pipes attached to said closure plate in spaced relation adjacent the edges thereof and penetrating said closure plate, said conduit pipes projecting into said container, a supply chamber attached to the ends of said pipes inside of said container in braced relation to reduce vibration thereof, a pair of supply pipes attached to opposite sides of said supply chamber, said pair of supply pipes extending axially substantially throughout the inner length of said container, and gravity operated valves for the free ends of said supply pipes, said conduit pipes being arranged on said closure plate so that said conduit pipes, said supply chamber, said supply pipes and said gravity valves may be inserted into said container through the mouth thereof assembled as a unit on said closure plate.

3. A fire extinguisher particularly adapted for use under conditions accompanied by considerable vibration, comprising: a one piece container having a relatively wide mouth, a closure plate fitted to said mouth in sealing relation, a discharge head attached to said container around the mouth thereof, said discharge head clamping said closure plate into said mouth, a supply chamber having a cross sectional size somewhat smaller than the area of said mouth to permit said supply chamber to be inserted into said container through said mouth, a plurality of pipes rigidly attached to and penetrating said closure plate at one of their ends, the other ends of said plurality of pipes being rigidly attached to said supply chamber and communicating with the interior thereof, said plurality of pipes being spaced on said closure plate to support said supply chamber in the inside of said container in braced relation to reduce vibration thereof substantially to a minimum, a pair of supply pipes attached to opposite sides of said supply chamber and extending axially substantially throughout the inner length of said container, and gravity operated valves for the free ends of said supply pipes.

4. A fire extinguisher liquid container for storing liquid under gas pressure, particularly adapt- -ed for extinguishing fires on aircraft, comprising:

a bottle, a discharge head secured in a fluid tight manner on to the mouth of said bottle, an interior closure member sealing the mouth of said bottle from said discharge head, a supply tube in said bottle extending almost throughout the length of said bottle, gravity operated closure valves having an opening area substantially equal to the effective cross-sectional area of said supply tube, said closure valves being disposed one at each end of said supply tube, a plurality of conduit pipes attached through said interior closure member at one of their ends in the spaced relation, and communicating means connected to said supply tube intermediate said valves for connecting the other ends of said conduit pipes to said supply tube in braced relation, said discharge head having an opening commensurate in size with the effective cross-sectional area of said supply tube and with that of said conduit pipe means so that the liquid from said bottle may be rapidly released and fed to a fire.

5. A fire extinguisher liquid container for storing liquid under gas pressure, particularly adapted for extinguishing fires on aircraft, comprising: a bottle, a discharge head secured in a fluid tight manner on to the mouth of said bottle, an interior closure member sealing the mouth of said bottle from said discharge head, a supply tube in said bottle extending almost throughout the length of said bottle, gravity operated closure valves having an opening area substantially equal to the effective cross-sectional area of said supply tube, said closure valves being disposed one at each end of said supply tube, a plurality of conduit pipes attached through said interior closure member at one of their ends in the spaced relation, and a supply chamber having a diameter larger than that of said supply tube, said supply chamber being connected to said supply tube intermediate said valves, the other ends of said conduit pipes being connected to said supply chamber in braced relation to hold said supply tube in said bottle in substantially rigid fashion,

said discharge head having an opening commensurate in size with the eflective cross-sectional area of said supply tube and with that of said conduit pipe means so that the liquid from said bottle may be rapidly released and fed to a fire.

6. A fire extinguisher liquid container for storing liquid under gas pressure, particularly adapted for extinguishing fires on aircraft, comprising: a bottle, a discharge head secured in a fluid tight manner on to the mouth of said bottle, an interier closure member sealing the mouth of said bottle from said discharge head, a supply tube in said bottle extending almost throughout the length of said bottle, gravity operated closure valves having an opening area substantially equal to the effective cross-sectional area of said supply tube, said closure valves being disposed one at each end of said supply tube, at least three conduit pipes attached through said interior closure member at one of their ends in the spaced relation, and communicating meansconnected to said supply tube intermediate said valves for connecting the other ends of said conduit pipes to said supply tube in braced relation to hold said supply tube in said bottle in substantially rigid fashion. HUBERT MACKENZIE SALMOND. ANDERS MATHISEN, 

